This section provides the steps required for a successful upgrade from Zabbix 3.4.x to Zabbix 4.0.x using official Zabbix packages for Red Hat Enterprise Linux/CentOS.
While upgrading Zabbix agents is not mandatory (but recommended), Zabbix server and proxies must be of the same major version. Therefore, in a server-proxy setup, Zabbix server and all proxies have to be stopped and upgraded.
To minimize downtime and data loss during the upgrade, it is recommended to stop and upgrade Zabbix server and then stop, upgrade and start Zabbix proxies one after another. When all proxies are upgraded, start Zabbix server. During the Zabbix server downtime, running proxies will keep collecting and storing data and will pass the data to Zabbix server when the server is up and running. Any notifications for problems during Zabbix server downtime will be generated only after the upgraded server is started.
Note that with SQLite database on proxies, history data from proxies before the upgrade will be lost, because SQLite database upgrade is not supported and the SQLite database file has to be manually removed. When proxy is started for the first time and the SQLite database file is missing, proxy creates it automatically.
Depending on database size the database upgrade to version 4.0 may take a long time.
Before the upgrade make sure to read the relevant upgrade notes!
The following upgrade notes are available:
|Upgrade from||Read full upgrade notes||Most important changes between versions|
|3.4.x||For 4.0||'libpthread' and 'zlib' libraries now mandatory;
Support for plain text protocol dropped and header is mandatory;
Pre-1.4 version Zabbix agents are no longer supported;
The Server parameter in passive proxy configuration now mandatory
|SQLite support as backend database dropped for Zabbix server/frontend;
Perl Compatible Regular Expressions (PCRE) supported instead of POSIX extended;
'libpcre' and 'libevent' libraries mandatory for Zabbix server;
Exit code checks added for user parameters, remote commands and system.run items without the 'nowait' flag as well as Zabbix server executed scripts;
Zabbix Java gateway has to be upgraded to support new functionality
|3.0.x LTS||For 3.2
|Database upgrade may be slow, depending on the history table size|
You may also want to check the requirements for 4.0.
It may be handy to run two parallel SSH sessions during the upgrade, executing the upgrade steps in one and monitoring the server/proxy logs in another. For example, run
tail -f zabbix_server.log or
tail -f zabbix_proxy.log in the second SSH session showing you the latest log file entries and possible errors in real time. This can be critical for production instances.
Stop Zabbix server to make sure that no new data is inserted into database.
If upgrading the proxy, stop proxy too.
It is known to be possible to upgrade the server only and have older, yet unupgraded proxies report data to a newer server (the proxies can't refresh their configuration though). This approach, however, is not recommended and not supported by Zabbix and choosing it is entirely at your own risk.
This is a very important step. Make sure that you have a backup of your database. It will help if the upgrade procedure fails (lack of disk space, power off, any unexpected problem).
Make a backup copy of Zabbix binaries, configuration files and the PHP file directory.
PHP files and Zabbix binaries:
To proceed with the upgrade your current repository package has to be updated.
To upgrade Zabbix components you may run something like:
If using PostgreSQL, substitute
pgsql in the command. If upgrading the proxy, substitute
proxy in the command.
See the upgrade notes for details on mandatory changes.
Start the updated Zabbix components.
After the upgrade you may need to clear web browser cookies and web browser cache for the Zabbix web interface to work properly.
It is possible to upgrade between minor versions of 4.0.x (for example, from 4.0.1 to 4.0.3). Upgrading between minor versions is easy.
To execute Zabbix minor version upgrade it is required to run:
To execute Zabbix server minor version upgrade run:
To execute Zabbix agent minor version upgrade run:
Note that you may also use 'update' instead of 'upgrade' in these commands. While 'upgrade' will delete obsolete packages, 'update' will preserve them.